The invention relates to a single-layer, polygonally-curved supporting frame structure in which pairs of bend points of the supporting structure bars are connected to one another by the tension members of a first set thereof and in which bend points intermediate those connected by the tension members of the first set are connected to one another by the tension members of a second set thereof to omit the bend points connected by the tension members of the first set. Single-layer polygonally-curved supporting frame structures can be used for barrel-shaped, dome-shaped or other double curved roof supporting structures.
Barrel-shaped and dome-shaped supporting structures have provided very economical types of covers. Under uniform loading and with ideal shaping, only compressive forces occur in such supporting structure systems. However, great deformation, and collapse, can occur as a result of additional loading one side, such as by large individual loads or horizontal loads due to wind, etc. Hitherto, this was prevented by the use of arched beams having high resistances to bending, arched frameworks or double-layer, curved frame structures which, in addition to forces normal to the direction of arch also were able to absorb large bending moments. This approach, however, resulted in heavier and thus less economical construction.
German Offenlegungsschrifts No. 2,800,720 and German Offenlegungsschrift No. 3,311,397 disclose single-layer, frame supporting structures of the above-mentioned type.
The roof construction disclosed by German Offenlegungsschrift No. 3,311,397 for covering halls, swimming pools, sewage plants and the like shows profiles bridging the span which are angled in the same direction at a plurality of points and run rectilinearly between the bend points. The profiles are arranged next to each other so that the bend points of each profile are located next to the center area between the bend points of each adjacent profile. Adjacent profiles are connected to one another by diagonal struts in the form of two legs abutting at an obtuse angle. The apex areas and leg ends of the diagonal struts are connected to the profiles at the bend points of the profiles. With regard to the joined diagonal bars, the "bend points" (namely, the apices and the leg ends) are in each case connected to one another by bars while omitting one bend point each in between.
German Offenlegungsschrift No. 2,800,720 relates to a framework construction in a modular design system for arched covers which are composed of a plurality of triangular supporting structures having a curved profile whose reticular shell consists of a rigid triangular and/or rhombic mesh. The sloping, bar-shaped elements defining the mesh can be drawn in geodetic lines running helically and crossing one another. German Offenlegungsschrift No. 2,800,720 discloses reinforcing tension bars which connect diagonally opposite corner points of a rhombic mesh, the adjacent corner points being "omitted."